5,959 research outputs found
Free wake analysis of hover performance using a new influence coefficient method
A new approach to the prediction of helicopter rotor performance using a free wake analysis was developed. This new method uses a relaxation process that does not suffer from the convergence problems associated with previous time marching simulations. This wake relaxation procedure was coupled to a vortex-lattice, lifting surface loads analysis to produce a novel, self contained performance prediction code: EHPIC (Evaluation of Helicopter Performance using Influence Coefficients). The major technical features of the EHPIC code are described and a substantial amount of background information on the capabilities and proper operation of the code is supplied. Sample problems were undertaken to demonstrate the robustness and flexibility of the basic approach. Also, a performance correlation study was carried out to establish the breadth of applicability of the code, with very favorable results
Travelling Down the Unsteady Path: United States v. Lopez, New York v. United States and the Tenth Amendment
Evolution of the Command Responsibility Doctrine in Light of the Celebici Decision of the International Criminal Tribunal for the Former Yugoslavia
Evolution of the Command Responsibility Doctrine in Light of the Celebici Decision of the International Criminal Tribunal for the Former Yugoslavia
3D Alchemy: a guide to 3D realistic computer graphics
Last year, many films and commercials took advantage of computer technology to create astonishing 3D animations. Examples such as the Listerine commercial series, the NBA logo on TV, and the Chip & Pepper TV cartoon, featured unique and vibrant computer images. Among the various animations, some were made by high end computer systems, but some simply by personal computers. Small, fast, and more capable personal computers are now performing professional-level video production roles and, in fact, they are a staple of many feature film productions and broadcast television facilities
Passive Scalar: Scaling Exponents and Realizability
An isotropic passive scalar field advected by a rapidly-varying velocity
field is studied. The tail of the probability distribution for
the difference in across an inertial-range distance is found
to be Gaussian. Scaling exponents of moments of increase as
or faster at large order , if a mean dissipation conditioned on is
a nondecreasing function of . The computed numerically
under the so-called linear ansatz is found to be realizable. Some classes of
gentle modifications of the linear ansatz are not realizable.Comment: Substantially revised to conform with published version. Revtex (4
pages) with 2 postscript figures. Send email to [email protected]
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